1. Field of the Invention
The present invention relates to a hydraulic excavator.
2. Background Information
An exhaust treatment apparatus is mounted onto a hydraulic excavator. The exhaust treatment apparatus is connected with an engine via a connecting pipe in order to treat exhaust from the engine. For example, as an example of the exhaust treatment apparatus, there is a diesel particulate filter apparatus. The diesel particulate filter apparatus reduces particulate matter in exhaust.
When the exhaust treatment apparatus is attached to the engine such that the exhaust treatment apparatus is supported by the engine, a heavy weight is arranged on the upper portion of the engine. As a result, the load on a bracket for attaching the exhaust treatment apparatus to the engine is increased. When the bracket is enlarged in order to strengthen the bracket, the weight of the bracket is increased.
Accordingly, it is preferable that the exhaust treatment apparatus be attached to a support other than the engine. For example, a table is arranged on an upper frame via supporting legs in Japan Patent Laid-open Patent Publication JP-A-2012-097413. A diesel particulate filter apparatus and a selective catalytic reduction apparatus are arranged on an upper surface of the table.
When the support is arranged on the upper frame as in Japan Patent Laid-open Patent Publication JP-A-2012-097413, the exhaust treatment apparatus is significantly affected by vibration from the upper frame. In contrast to this, the connecting pipe which connects the exhaust treatment apparatus and the engine is significantly affected by vibration of the engine. As a result, a load acts on the connecting pipe due to the difference in vibration between the engine and the support.
It is possible for the difference in vibration described above to be absorbed by providing a bellows portion in the connecting pipe. However, when the bellows portion is provided in the connecting pipe, the connecting pipe changes shape in a flexible manner in the bellows portion. Accordingly, in a state where the connecting pipe is a cantilever, it is difficult to hold the end portion of the connecting pipe at a constant position. In particular, it is preferable that the length of the bellows portion be increased in order to increase the vibration absorption capability of the bellows portion. However, when the length of the bellows portion is large, it is more difficult to hold the end portion of the connecting pipe at a constant position. As a result, an operation where the connecting pipe is connected with the exhaust treatment apparatus is difficult. Alternatively, an operation where the connecting pipe is detached from the exhaust treatment apparatus is difficult.
An object of the present invention is to provide a hydraulic excavator where it is possible to reduce the load on a connecting pipe due to vibration and where it is possible to eliminate difficulties when attaching and detaching the connecting pipe with regard to an exhaust treatment apparatus.
A hydraulic excavator according to a first aspect of the present invention is provided with an engine, a revolving frame, a vehicle body frame, a first exhaust treatment apparatus, and a connecting pipe. The revolving frame supports the engine. The vehicle body frame includes a plurality of column members which are disposed upright on the revolving frame. The first exhaust treatment apparatus is supported by the vehicle body frame. The first exhaust treatment apparatus treats exhaust from the engine. At least a portion of the connecting pipe has a bellows portion which is able to extend and contract. The connecting pipe connects the engine and the first exhaust treatment apparatus. The connecting pipe includes a fixing portion which is fixed to the vehicle body frame. The fixing portion is positioned in the connecting pipe between the bellows portion and the first exhaust treatment apparatus.
A hydraulic excavator according to a second aspect of the present invention is the hydraulic excavator according to the first aspect, where a connecting portion of the connecting pipe and the first exhaust treatment apparatus is positioned below the first exhaust treatment apparatus.
A hydraulic excavator according to a third aspect of the present invention is the hydraulic excavator according to the second aspect, where the fixing portion is positioned below the connecting portion.
A hydraulic excavator according to a fourth aspect of the present invention is the hydraulic excavator according to any of the first to third aspects, where the fixing portion and the first exhaust treatment apparatus are attached to the same member in the vehicle body frame.
A hydraulic excavator according to a fifth aspect of the present invention is the hydraulic excavator according to any of the first to third aspects, where the vehicle body frame further includes a beam member to which the first exhaust treatment apparatus is attached. The fixing portion is fixed to the beam member.
A hydraulic excavator according to a sixth aspect of the present invention is the hydraulic excavator according to any of the first to third aspects, which is further provided with an attachment member for attaching the fixing portion to the vehicle body frame. The attachment member includes a first plate portion and a second plate portion. The attachment member has a shape which is bent between the first plate portion and the second plate portion. The first plate portion and the fixing portion are configured to be attached to each other so as to be able to be positionally adjusted. The second plate portion and the vehicle body frame are configured to be attached to each other so as to be able to be positionally adjusted.
A hydraulic excavator according to a seventh aspect of the present invention is the hydraulic excavator according to any of the first to third aspects, which is further provided with a second exhaust treatment apparatus. The second exhaust treatment apparatus is supported by the vehicle body frame. The second exhaust treatment apparatus treats exhaust from the engine. The engine, the second exhaust treatment apparatus, and the first exhaust treatment apparatus are arranged so as to line up in a first direction on a horizontal plane in a planar view in order of the engine, the second exhaust treatment apparatus, and the first exhaust treatment apparatus.
A hydraulic excavator according to an eighth aspect of the present invention is the hydraulic excavator according to the seventh aspect, where the connecting pipe is connected with the first exhaust treatment apparatus by passing below the second exhaust treatment apparatus.
A hydraulic excavator according to a ninth aspect of the present invention is the hydraulic excavator according to the seventh aspect, which is further provided with a bracket for attaching the first exhaust treatment apparatus to the vehicle body frame. The first exhaust treatment apparatus and the second exhaust treatment apparatus are attached to the vehicle body frame in an integral manner via the bracket.
A hydraulic excavator according to a tenth aspect of the present invention is the hydraulic excavator according to the seventh aspect, where the first exhaust treatment apparatus and the second exhaust treatment apparatus are arranged to line up in a state where the longitudinal directions of the first exhaust treatment apparatus and the second exhaust treatment apparatus are perpendicular with the first direction. The length of the bellows portion is larger than the dimension of the first exhaust treatment apparatus in the first direction or the dimension of the second exhaust treatment apparatus in the first direction.
A hydraulic excavator according to an eleventh aspect of the present invention is the hydraulic excavator according to the tenth aspect, where the second exhaust treatment apparatus has a cylindrical shape. The length of the bellows portion is larger than the diameter of the second exhaust treatment apparatus.
A hydraulic excavator according to a twelfth aspect of the present invention is the hydraulic excavator according to the tenth aspect, where the first exhaust treatment apparatus has a cylindrical shape. The length of the bellows portion is larger than the diameter of the first exhaust treatment apparatus.
A hydraulic excavator according to a thirteenth aspect of the present invention is the hydraulic excavator according to the seventh aspect, where the first exhaust treatment apparatus and the second exhaust treatment apparatus are arranged to line up in a state where the longitudinal directions of the first exhaust treatment apparatus and the second exhaust treatment apparatus are perpendicular with the first direction. The length of the connecting pipe in the first direction is larger than the distance between the center of the first exhaust treatment apparatus in the first direction and the center of the second exhaust treatment apparatus in the first direction.
A hydraulic excavator according to a fourteenth aspect of the present invention is the hydraulic excavator according to the seventh aspect, where the second exhaust treatment apparatus is a selective catalytic reduction apparatus.
A hydraulic excavator according to a fifteenth aspect of the present invention is the hydraulic excavator according to any of the first to third aspects, where the first exhaust treatment apparatus is a diesel particulate filter apparatus.
In the hydraulic excavator according to the first aspect of the present invention, it is possible to absorb a difference in vibration between the engine and the vehicle body frame using the bellows portion of the connecting pipe. Due to this, the load on the connecting pipe is reduced. In addition, the connecting pipe is fixed to the vehicle body frame at the fixing portion between the bellows portion and the first exhaust treatment apparatus. As a result, it is easy to hold the end portion of the connecting pipe at a constant position even in a state where the end portion of the connecting pipe is not connected with the first exhaust treatment apparatus. Due to this, an operation where the connecting pipe is attached and detached with regard to the exhaust treatment apparatus is easy.
In the hydraulic excavator according to the second aspect of the present invention, the connecting portion of the connecting pipe and the first exhaust treatment apparatus is positioned below the first exhaust treatment apparatus. Accordingly, it is possible to detach the first exhaust treatment apparatus from the vehicle by lifting up the first exhaust treatment apparatus while maintaining a state where the connecting pipe is attached to the vehicle body frame.
In the hydraulic excavator according to the third aspect of the present invention, the fixing portion is positioned below the connecting portion. Accordingly, the distance from the fixing portion up to the end portion of the connecting pipe which is connected with the first exhaust treatment apparatus is short. As a result, it is easier to hold the end portion of the connecting pipe at a constant position.
In the hydraulic excavator according to the fourth aspect of the present invention, the fixing portion and the first exhaust treatment apparatus are attached to the same member in the vehicle body frame. As a result, it is possible to reduce errors in the positions of the end portion of the connecting pipe and the first exhaust treatment apparatus.
In the hydraulic excavator according to the fifth aspect of the present invention, the fixing portion is fixed to a beam member in the same manner as the first exhaust treatment apparatus. Accordingly, the distance from the fixing portion up to the end portion of the connecting pipe which is connected with the first exhaust treatment apparatus is short. As a result, it is easier to hold the end portion of the connecting pipe at a constant position.
In the hydraulic excavator according to the sixth aspect of the present invention, it is possible to adjust the position of the fixing portion in a plurality of directions by adjusting the position of the first plate portion and adjusting the position of the second plate portion. As a result, there is a high degree of freedom in positional alignment of the fixing portion. Due to this, the operation where the connecting pipe is attached and detached with regard to the first exhaust treatment apparatus is easier.
In the hydraulic excavator according to the seventh aspect of the present invention, the engine, the second exhaust treatment apparatus, and the first exhaust treatment apparatus are arranged to line up a planar view in this order in the first direction. That is, the first exhaust treatment apparatus is positioned to be further from the engine than the second exhaust treatment apparatus. Accordingly, it is possible to ensure that the lengths of the connecting pipe and the bellows portion are large. Due to this, it is possible to further reduce the load on the connecting pipe due to vibration.
In the hydraulic excavator according to the eighth aspect of the present invention, the connecting pipe passes below the second exhaust treatment apparatus. Accordingly, it is difficult for the connecting pipe to interfere with the second exhaust treatment apparatus when detaching the second exhaust treatment apparatus from the vehicle by lifting up the second exhaust treatment apparatus.
In the hydraulic excavator according to the ninth aspect of the present invention, the first exhaust treatment apparatus and the second exhaust treatment apparatus are made into a unit using the bracket. Accordingly, it is possible to attach and detach the first exhaust treatment apparatus and the second exhaust treatment apparatus to and from the vehicle body frame integrally as a unit. In addition, when attaching and detaching the unit with regard to the vehicle body frame, the end portion of the connecting pipe is held at a constant position by the fixing portion. Due to this, when the unit is attached to the vehicle body frame, the operation where the connecting pipe is connected with the first exhaust treatment apparatus is easy. Alternatively, when the unit is detached from the vehicle body frame, the operation where the connecting pipe is detached from the first exhaust treatment apparatus is easy.
In the hydraulic excavator according to the tenth aspect of the present invention, it is ensured that the length of the bellows portion is large. Due to this, it is possible to further reduce the load on the connecting pipe due to vibration.
In the hydraulic excavator according to the eleventh aspect of the present invention, it is ensured that the length of the bellows portion is large. Due to this, it is possible to further reduce the load on the connecting pipe due to vibration.
In the hydraulic excavator according to the twelfth aspect of the present invention, it is ensured that the length of the bellows portion is large. Due to this, it is possible to further reduce the load on the connecting pipe due to vibration.
In the hydraulic excavator according to the thirteenth aspect of the present invention, it is ensured that the length of the bellows portion is large. Due to this, it is possible to further reduce the load on the connecting pipe due to vibration.
In the hydraulic excavator according to the fourteenth aspect of the present invention, pollutants such as nitrogen oxide NOx in the exhaust are purified by the second exhaust treatment apparatus.
In the hydraulic excavator according to the fifteenth aspect of the present invention, particulate matter which is included in the exhaust is captured by the first exhaust treatment apparatus. In addition, the diesel particulate filter apparatus is frequently maintained. Accordingly, it is possible to improve maintainability of the first exhaust treatment apparatus due to the operation where the connecting pipe is attached and detached with regard to the first exhaust treatment apparatus being easy.